package/poppler: fix build failure due to gcc bug 68485

The bullet package exhibits gcc bug 68485 when built for the Microblaze
architecture with optimization enabled, which causes a build failure.

As done for other packages in Buildroot work around this gcc bug by
setting optimization to -O0 if BR2_TOOLCHAIN_HAS_GCC_BUG_68485=y like we
already do for BR2_TOOLCHAIN_HAS_GCC_BUG_85180=y.

Fixes:
http://autobuild.buildroot.net/results/96e77ddba5042ba4dacb16b328fc298a4f00f49a/

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/poppler/poppler.mk

@@ -131,4 +131,12 @@ else
 POPPLER_CONF_OPTS += -DUSE_FLOAT=ON
 endif
 
+POPPLER_CXXFLAGS = $(TARGET_CXXCFLAGS)
+
+ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_68485),y)
+POPPLER_CXXFLAGS += -O0
+endif
+
+POPPLER_CONF_OPTS += -DCMAKE_CXX_FLAGS="$(POPPLER_CXXFLAGS)"
+
 $(eval $(cmake-package))